Windows, doors, skylights and structural components made from materials such as aluminum, alloys thereof, steel and plastics are known. For example, window and door assemblies may be made from aluminum alloy extrusions. Windows manufactured with aluminum frame and thermal break components are also known. For example, manufacturers use pour-and-debridge and crimped polyamide strips to make aluminum windows with thermal breaks. The pour-and-debridge type window uses liquid polyurethane poured in the pocket of an aluminum extrusion. After the polyurethane solidifies, the aluminum backing of the pocket is cut away. The process involves four different operations: polyurethane mixing, lancing the aluminum extrusion, abrasion conditioning of the aluminum extrusion and cutting the backing of the thermal break. The crimped polyamide method uses polyamide (or other polymer) strips that are crimped at both ends into the internal and external aluminum extrusions of the window frame. In this case, the manufacturing process requires three different operations: knurling the aluminum extrusions, inserting the polyamide and crimping the aluminum extrusions. Windows that use pour-and-debridge thermal breaks may have a general U factor of about 0.5 Btu/h ft2 F and windows that use crimped polyamide may have a general U factor of about 0.3 Btu/h ft2 F. This corresponds to about an R3 thermal resistance. Both of these technologies require a significant number of manufacturing steps and expensive manufacturing equipment. Alternative methods, apparatus and manufactures for modifying energy transfer through windows, doors and other structural components remains desirable.